In a number of roller bearing applications, it is necessary to arrange a sensor in a correct position and alignment with respect to a signal transmitter and then to fasten it. Especially revolutions per minute (rpm) sensors that interact with the signal transmitter that is fastened on a rotating part of the roller bearing can only function with a specific detection distance between sensor and signal sender.
For example, in wheel bearings in motor vehicles, so-called rpm sensors are used for anti-lock braking systems in which a subsequent deviation from the optimal detection distance can lead to a signal loss that limits the function of the anti-lock braking system or even suppresses it. The rpm sensors are mostly based on magnetic effects, e.g., the Hall effect, the magnetorestrictive effect or induction. However, similar problems exist in roller bearings in the aviation industry, e.g., roller bearings for jet engines, or even in roller bearings for rolling mills and paper-making machines.
On the one hand, the fastening must be secure enough in order to prevent a subsequent position change or an incorrect fastening during the sensor installation. On the other, the fastening should have few separate components and be designed simply, in order to keep the process cost-efficient.
A sensor for an angular ball bearing is known from U.S. Pat. No. 5,640,087, in which the sensor is mounted in a fixed flange on the stub axle. The housing of the sensor has a spring element, which can be loaded in a radial direction, with a latching tab. This latching tab is provided for engagement in a groove, which determines the axial position of the sensor. When it snaps in, it is possible to recognize that the sensor is arranged in the correct position. After that, there is an essentially disk-shaped fastening element that is fastened with axial positive connection to the sensor by means of a screw on the fixed flange.
A revolution per minute (rpm) sensor for an angular ball bearing is known from German Reference 69111879 T5 that is mounted in a fastening flange of the wheel bearing, whereby the fastening flange forms a part of the fixed stub axle.